HTTP Post
To thoroughly test data loss prevention (DLP) software, it is recommended to use the HTTP post test and HTTPS post test. These tests allow you to check if your DLP solution can block traffic by attempting to send an HTTP or HTTPS post request. This test page is set up to simulate a post request without saving any data.
If this page loaded with SSL, here is a redirect URL http://dlptest.com/http-post/ or just remove the S.
What is a HTTP Post?
A HTTP POST is a request method supported by the HTTP protocol. By design, the POST request method requests that a web server accept the data enclosed in the body of the request message, most likely for storing it. It is often used when uploading a file or when submitting a completed web form. Here at dlptest.com we don’t store any info from the HTTP Post but most websites will store your data.
More info can be found on good old wikipedia
https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol#Request_methods